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Atacama Cosmology Telescope (ACT)

Product Name
ACT 3-year CMB Likelihood
Mission
ACT

Description

Oct-2013 Updated likelihood v2p2 released with updated ACT beams, including the improved binning of the spectra used in v2p1. As reported in the ACT papers, the effect of this change on cosmological parameters is small, at the 0.1 sigma level.

This is the software used by the ACT collaboration to compute the likelihood of cosmological models, using the small-scale CMB power spectrum from 500 < l <3500 measured by ACT, derived from the 3-year data (2008-2010 observations). This spectrum has already been marginalized over SZ and foreground emission, so no additional nuisance parameters are required to be sampled. The likelihood is a simple chisq summed over the 42 ACT-E and ACT-S data points (21 bins for each). It is based on the WMAP team's likelihood software.

As an option it also includes the likelihood for the 650 < l<3000 points measured by SPT (47 bins), also marginalized over foregrounds. When ACT and SPT are used together, only the ACT-E data points are used.

To build, modify the Makefile to reflect your system's environment. Then

> make # Compiles the likelihood software and builds a test program.

> ./test # Runs the test program.

Please reference Dunkley et al. 2013 and Das et al. 2013 if you use this code, and Calabrese et al. 2013 if you include the SPT likelihood. The SPT data are derived from Story et al 2012.

Additional Details

  • "The Atacama Cosmology Telescope: Likelihood for small-scale CMB data," J. Dunkley, et al.(2013), astro-ph/1301.0776
  • "The Atacama Cosmology Telescope: temperature and gravitational lensing power spectrum measurements from three seasons of data", S. Das, et al. (2013), astro-ph/1301.1037
  • "The Atacama Cosmology Telescope: cosmological parameters from three seasons of data", J. Sievers, et al. (2013), astro-ph/1301.0824

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